Ensure png, jpeg and gif decoders don't use DilloImage after set_parms()

This allows reuse of the dicache entry after repush changes DilloImage.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/jpeg.c b/src/jpeg.c
index 625808fb..5652aa56 100644
--- a/src/jpeg.c
+++ b/src/jpeg.c
@@ -304,6 +304,7 @@ static void Jpeg_write(DilloJpeg *jpeg, void *Buf, uint_t BufSize)
                              (uint_t)jpeg->cinfo.image_width,
                              (uint_t)jpeg->cinfo.image_height,
                              type, 1 / 2.2);
+         jpeg->Image = NULL; /* safeguard: may be freed by its owner later */
 
          /* decompression step 4 (see libjpeg.doc) */
          jpeg->state = DILLO_JPEG_STARTING;